We have been reading with great interest the study by Ferrando et al.1 We appreciated the elegant experimental approach undertaken by the authors to demonstrate distribution and precise tissue/cell expression pattern of knock-in protein targets tagged with a 3 × FLAG epitope. This article conveys an important piece of information, and the described technique complements the body of IHC staining protocols that are currently available to detect products of other commonly used reporter systems in formalin-fixed and paraffin-embedded sections. We noticed, however, that the Materials and Methods section does not report the exact anti-FLAG antibody used to carry out these experiments. The authors mentioned a goat polyclonal from Abcam, and the company has at least three different products that may fit this description.
Sincerely yours,
Enrico Radaelli and Matteo Riva
Literature Cited
- 1. Ferrando RE, Newton K, Chu F, Webster JD., French DM. Immunohistochemical detection of FLAG-tagged endogenous proteins in knock-in mice. J Histochem Cytochem. 2015;63(4):244–55. [DOI] [PMC free article] [PubMed] [Google Scholar]